Volume 63, Issue 1

The micellization behavior of mixed micellar systems containing cetyldiethylethanolammonium bromide (CDEEAB) and cetyltriphenylphosphonium bromide (CTPB) surfactants with 10 % (v/v) and 20 % (v/v) solvents i.e. dimethyl sulfoxide (DMSO) and dimethylformamide (DMF) were investigated using conductivity and surface tension measurements at 300 K. Critical micelle concentration (CMC) values increases with increasing mole fraction of CDEEAB. The interfacial properties, Γ max (maximum surface excess), Α min (minimum surface area per molecule) and π CMC (surface pressure at the CMC) have been determined. The Clint equation, Rosen and Rubingh models have been used to calculate interaction parameters ( β m and β σ ). The findings show that protonic solvents change the physicochemical characteristics of the cationic surfactants and significantly improve synergistic interactions. Interestingly, the addition of DMSO (10–20 % v/v) causes a significant increase in the CMC of the CDEEAB + CTPB mixed system. This effect is more noticeable than that of DMF, demonstrating the solvent-dependent modulation of mixed micelle formation. Thermodynamic parameters, Δ G a d s o ${\Delta \mathrm{G}}_{ads}^{o}$ , Δ G e x o ${\Delta \mathrm{G}}_{ex}^{o}$ , Δ G m   o   ${\Delta \mathrm{G}}_{m\hspace{0.17em}}^{o\hspace{0.17em}}$ values are negative indicating the stability and spontaneity of the mixed micelle.

A novel non-foaming surfactant, propoxylated bisphenol A phosphate ester salt, integrating Extended and Bola-type surfactant characteristics, was synthesized via phosphorylation of propoxylated bisphenol A with phosphorus pentoxide. Its structure was characterized by FTIR and 1 H/ 31 P NMR. The critical micelle concentration and heat resistance were investigated by using an automated surface tension meter and thermal gravimetric analyzer, and the surface properties, such as water solubility, emulsibility, and foaming, were studied and evaluated. The experimental results showed that the product was soluble in water at room temperature, its aqueous solution had two cmc points with polymer surfactant properties, and its γ cmc was 32.97 and 32.70 mN m −1 , when the concentration was 1 % and 2 %, with good surface activity. It had excellent high-temperature resistance, with an initial decomposition temperature of 286.35 °C, and a maximum decomposition temperature of 295.66 °C. The thermal weight loss residue at 500 °C was 12.34 %, and the residual rate at 600–700 °C was stable at 10.85 %. The surfactant was intrinsically non-foaming, had high surface activity, strong emulsifying power, good penetration, excellent compatibility, and had good resistance to high temperature, acid, alkali, and oxidation.

Furosemide, a diuretic for managing edema in premature neonates and infants with congestive heart failure, is often formulated with alcohol and preservatives, posing risks like neurotoxicity and cardiovascular complications. This study aimed to develop a safe, alcohol-and preservative-free micellar liquid formulation of furosemide for pediatric use. Drug-loaded micelles were prepared using Kolliphor RH 40 (polyoxyl 40 hydrogenated castor oil) as a surfactant and hydroxypropyl-beta-cyclodextrin as a solubiliser and characterized for size, morphology, zeta potential, polydispersity, critical micelle concentration, stability, and microbiological quality. Of the twelve formulations, F11 and F12 were selected for their visual clarity and physical properties. The optimised batch (F11) formed nanosized micelles (19.16 ± 0.06 nm) with uniform distribution (PDI 0.292 ± 0.02) and steric stabilisation (zeta potential −0.43 ± 0.01 mV). Entrapment efficiency exceeded 98 %, and transmittance was >97 %, confirming high clarity. The formulation remained stable in SGF and SIF for 12 h with >99 % assay retention and complies with the stability protocol. The data obtained from stability studies indicate the physical, pharmaceutical, and microbial stability of the developed formulation. This alcohol- and preservative-free micellar formulation may offer a safe and effective treatment option for paediatric populations.

In gas well operations, efficient foam drainage and prevention of hydrate aggregation are crucial for maintaining production efficiency and preventing blockages. This study presents a novel dual-functional surfactant system (TPS) composed of cetyltrimethylammonium chloride (CTAC), alkylphenol ethoxylate (OP-10), and sodium dodecyl sulfate (SDS), designed to enhance both foam drainage and hydrate anti-aggregation. The optimized TPS formulation (0.05 % CTAC + 0.5 % OP-10 + 0.02 % SDS) demonstrated exceptional foaming ability with an initial foam volume of 540 ml and a half-life of 7.5 min at 50 °C. The system maintained high liquid-carrying capacity (72.5 %) even at elevated temperatures (65 °C) and in the presence of methanol, which is commonly used as a hydrate inhibitor. Differential scanning calorimetry (DSC) and microscopic observations revealed that TPS significantly reduced the phase transition temperature of tetrahydrofuran (THF) hydrates, thereby suppressing hydrate formation and aggregation. The compatibility of TPS with polyvinylpyrrolidone (PVP), a common kinetic hydrate inhibitor and foam stabilizer, enhanced foam stability. This dual-functional system offers a robust solution for improving gas well productivity and mitigating hydrate-related risks, with potential applications in complex oil and gas field environments.